DOI: https://doi.org/10.55373/mjchem.v26i6.72

Keywords: Activated carbon; paracetamol; photocatalysis; titanium dioxide; water recovery

Abstract

The current work describes the facile fabrication and characterization of activated carbon (AC)-supported titanium dioxide (TiO₂) photocatalysts for the degradation of paracetamol under low intensity UVC light. The synthesized photocatalysts were characterized using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) and ultraviolet–visible, near-infrared (UV–vis NIR) spectrophotometry. The effect of varying TiO₂ content with different mass ratios of AC and TiO₂ on the catalytic activity was thoroughly examined. SEM images of the AC-TiO₂ composites exhibited rough surfaces with small, aggregated particles on top. XRD patterns of pure TiO₂ and AC-TiO₂ showed characteristics of anatase. Optical characterization results showed that the TiO₂ and AC-TiO₂ composite photocatalysts displayed a strong emission peak at 408 nm in PL analysis and reduced band gap energies for the AC-TiO₂ composites compared to pure TiO₂, in the range of 3.13–3.18 eV. The results indicate that the incorporation of up to 1.5 g of TiO₂ on AC significantly enhanced the degradation efficiency of paracetamol to a maximum of ~90 %. The rate constants k1 and k2 were 0.0165 and 0.8684 min-1, respectively. The pseudo second-order model was shown to be the best-fitting model for the breakdown of paracetamol in aqueous solution. The electron-hole pairs were spatially separated due to strong and advantageous interactions between TiO₂ and AC, which inhibited charge recombination. This led to higher degradation percentages with increased TiO₂ content. The AC-TiO₂ composite photocatalysts exhibit promising potential for degrading pharmaceutical pollutants under environmentally relevant conditions.